Steam generating system



Aug. 2,1, 1934.

c. A. FRENCH STEAM GENERATING SYSTEM Filed May 24,l 1955 Patented Aug. 21, 1934 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to a steam power plant.

More specifically it relates to means for controlling the functioning of the various mechanisms making up an automatic power plant ,5' utilizing a semi-flash type boiler with forced circulation.

The principal object of the invention is the provision of automatic controls operable by conditions in the system for assuring the continued performance of the power plant and for preventing the operation of any portion thereof which might result in damage to the plant when conditions in the system are not conducive to proper functioning.

The drawing shows diagrammatically a steam power plant embodying the novel features of the invention. A casing 1 encloses a preheating coil 2, a vaporizing coil 3, and a superheating coil 4. A feed water pump 5 connected by a conduit 6 with a hot well 7 is operable to deliver water at a pressure above that of the boiler pressure through a conduit 8 to the preheating coil 2. Check valves 9 are provided on each side of the feed water pump 5. A second check valve 10 is also provided in the conduit 8 on the high pressure side of the feed water pump.

The preheating coil 2 terminates in a nozzle 11 positioned in a small chamber 12, which communicates with a vaporizing coil 3. A conduit 13 communicating with the bottom of a storage drum 14 also communicates with the chamber 12. Check valves 15 and 16 are positioned in the conduit 13. Between said valves a chamber 17 communicates with the conduit 13 and with the conduit 8. A plunger 18, slidably mounted in the chamber 17, and a spring 19 form a shock pump.

A by-pass conduit 20 connects with the feed water conduit 8 and with a chamber 21. The chamber 21 is divided by a partition 22, which has a centrally disposed opening therein. In the upper portion of the chamber, a bellows 23 seats against a cap 24, to which a valve stem 25 is rigidly secured. A valve 26 secured to the stem 25 is adapted to control the central opening in the partition 22. A coil compression spring 27, seating against the partition 22 and against the cap 24, closes the valve when the pressure in the bellows 23 is below the actuating amount. Above the partition in the chamber 21, a conduit 28 communicates with a conduit 29 leading to the low pressure side of the feed water pump. A second by-pass conduit 30 joins the conduit 20 with a chamber 31. The conduit 29 also com- 55 mu'nicates with the chamber 31 on the other side of a partition 32 therein. The partition 32 is provided with a centrally located opening which is adapted to be controlled by a valve 33. The valve 33 is rigidly connected to a temperature expansible element 34. A spring 35 seats against 60 the chamber 31 and against the end of the element 34 to hold the valve 33 open until the temperature in the element 34 reaches a degree at which the device is constructed to operate. A conduit 36 connects one end of the element 65 34 with a conduit 37 communicating with the top of the storage drum 14. The other end of the conduit 34 is connected by a pipe 38 with the lower end of the storage drum. The conduit 37 also communicates with the bellows 23 70 and transmits the boilerpressure to said bellows. A bleed valve 39 is positioned in the conduit 30.

A burner 40 positioned at the top of the boiler casing 1 is adapted to supply heat to the coils.

A fuel pump 41 draws fuel through a conduit 42 76 from a fuel tank 43 and forces it through a conduit 44 to the burner. A conduit 45 connected to the conduit 44 leads to a by-pass chamber 46. The by-pass chamber is connected by a conduit 47 to the fuel reservoir 43. A pressure expan- 80 sible bellows 4 8 is positioned in the bottom of the chamber 46 and connected by a conduit 49 to the high pressure side of the feed water pump.

A valve 50 is mounted above the bellows 48 and is adapted to close the conduit 45 upon ex- 85 pansion of said bellows. A by-pass conduit 51 connects the conduit 44 with the conduit 47. A valve 52 is positioned in the conduit 51 and is adapted to be manually operated to form a constant orifice by-pass.

A conduit 53 supplies air to the burner 40. A butterfly Valve 54 positioned in the conduit 53 is adapted to be operated by a plunger 55 operatively connected thereto. A spring 56 seats against the plunger 55 and normally maintains 95 the valve 54 in closed position. The plunger 55 fits into a cylinder 57 and is adapted to be reciprocated therein. A conduit 58 communicates with the lower portion of the cylinder 57 and with the conduit 49, transmitting thereto the feed water pump pressure. A valve 59 is positioned in the conduit 58.

The superheating coil 4 communicates with the storage drum 14 near the upper end thereof and is adapted to be connected to a steam consuming means, such as the steam cylinder 60. Exhaust steam from the cylinder is delivered to a condenser 61. The condensate from the condenser flows back into the hot well 7. A conduit 62, controlled by a valve 63, forms a no and with the conduit 6.

In the operation of this device, the feed water pump 5 is operated to deliver water against the boiler pressure through the conduit 8 to the preheating coil 2. The nozzle 11 has an ejector action which draws water through the conduit 13 from the storage drum and forces it together with the feed Water being `supplied through the vaporizing coil 3. The mixture of steam and water is delivered tangentially into the storage drum 14 whereby the water and steam are separated. Steam is withdrawn and preheated in the coil 4, thereafter being supplied to the steam cylinder 60.

To increase the flow of water from the storage drum through the coil 13, the shock pump is positioned between the valves 15 and 16. At each stroke of the feed water pump 5, the plunger 18 is forced upwardly against the compression of the spring 19, whereby water between the valves 15 and 16 is forced into the chamber 12. 'Ihe pressure on the delivery side of the feed water pump is transmitted at all times to the conduit 49 which communicates with the bellows 48 and controls the valve 50. Thevalve 50 is open at all times unless the feed water pump is operating to build up a suiicient pressure. When the valve 50` is open, oil fuel is by-passed into the reservoir 43 and cannot, therefore, be delivered to the burner with the resultant destruction of the coils in the boiler casing 1. The pump 41 is of a capacity greater than necessary for the burner 40. The conduit 51 is, therefore, provided as a by-pass through which fuel in amounts determined by the setting of the valve 52 is by-passed back to the reservoir 43.

The valve 54 in the air supply conduit 53 is also operated by the pressure in the conduit 49, which is transmitted through the conduit 58 to the cylinder 57. The valve 54 remains closed, whereby air cannot be supplied to the burner until the feed water pressure is sufficient to force the plunger 55 upwardly against the action of the spring 56. The valve 59 in the conduit 58 may be regulated to provide a time-like action in the operation of the valve 54.

The conduit 62 provides a constant by-pass in amounts regulated by the valve 63. This construction is used, as it is desirable to utilize a feed water pump which has a capacity greater than necessary for the boiler during any period of its operation.

The conduit 20 leading to the by-pass chamber 21 and the conduits 28 and 29, together with the elements in the by-pass chamber, forms a pressure operated means for by-passing the feed water at predetermined boiler pressures. 'Ihe conduit 30, the valve 39, chamber 31, and the elements associated therewith form a temperature controlled means operable by the water level in the storage drum to cut 0E the by-passwhen the water level in the storage drum 14.

lowers below the level at which the element 34 is positioned. It will be understood that, when this condition arises, steam will be delivered to the element 34, expanding said element and closing the opening in the partition 32. The valve 39 is'adjusted normally to form a bleed line through which a portion of the excess water delivered by the feed water pump is by-passed back to the intake side thereof.

The features making up the steam system described provide a cooperating system of automatic controls, whereby the conditions in the system regulate the supply of fuel, air and Water in such a manner that injury or dangerous conditions cannot be brought about in the system.

It is to be understood that applicant has shown only a preferred embodiment of his improved steam plant and that he claims as his invention all modifications thereof falling within the scope of the appended claims.

What is claimed as new is:

1. In a steam power plant, steam generating pressure to said coils, a storage drum with which said coils communicate, a by-pass conduit leading from the high pressure side of the feed water supply means, a valve in said conduit operable by the pressure in the storage drum, a second by-pass conduit communicating with the high pressure side of the water supply means, a valve in said conduit operable by the water level in the storage drum to close said conduit when water in the storage drum falls below a predetermined level, and a burner positioned to supply heat to the coils.

2. In a steam power plant, steam generating coils, means for supplying feed water under pressure to said coils, a storage drum with which said coils communicate, a by-pass conduit leading from the high pressure side of the feed water supply means, a valve in said conduit operable by the pressure in the storage drum. a second by-pass conduit communicating with the high pressure side of the water supply means, a valve in said conduit operable by the water level in the storage drum to close said conduit when water in the storage drum falls below a predetermined level, a burner positioned to supply heat to the coils, a fuel reservoir, a pump operable to deliver fuel from the reservoir to the burner, a by-pass conduit leading from the delivery side of the pump to the reservoir, a valve in said conduit operated by the pressure in the feed water conduit, an air supply conduit leading to said burner, a valve in said conduit, and means operable by the pressure on the delivery side of the feed water pump to control said valve.

CHARLES A. FRENCH. 

